Elevated microbial tolerance to metals and antibiotics in metal-contaminated industrial environments

To test the hypothesis that industrial metal contaminants select for microorganisms tolerant to unrelated agents, such as antibiotics, we analyzed metal and antibiotic tolerance patterns in microbial communities in the intake and discharge of ash settling basins (ASBs) of three coal-fired power plants. High-throughput flow-cytometric analyses using cell viability probes were employed to determine tolerances of entire bacterioplankton communities, avoiding bias toward culturable versus nonculturable bacteria. We found that bacterioplankton collected in ASB discharges were significantly more tolerant to metal and antibiotic exposures than bacterioplankton collected in ASB intakes. Optical properties of microorganisms collected in ASB discharges indicated no defensive physiological adaptations such as formation of resting stages or excessive production of exopolymers. Thus, it is likely that the elevated frequency of metal and antibiotic tolerances in bacterioplankton in ASB discharges were caused by shifts in microbial community composition, resulting from the selective pressure imposed by elevated metal concentrations or organic toxicants present in ASBs.     

The peculiarities of sprayed liquid’s thermal state change,as droplets are heated by conduction

The change of thermal state and phase transformation intensity of sprayed water, n-hexane, n-heptane and n-decane is numerically modelled in the case, as droplets are heated by conduction; the influence of the Knudsen layer is neglected; warming and evaporation of the droplets has no influence on the state of the carrying air flow. The research results prove that a peculiar change of the thermal state of sprayed liquid, irrespective of droplet’s dispersivity, exists in the time scale, expressed by Fourier number. The above-mentioned change can be conveniently defined by the characteristic curves, representing the change of a droplet surface, centre, and mean mass temperatures, which are sensibly influenced by temperature of gas mixture and partial pressure of liquid vapour in it. As these characteristic curves were expressed in regards to the initial and equilibrium evaporation temperatures of liquid, the universal curves, representing the change of thermal states of the examined liquids, were obtained in the time scale, expressed by Fourier number. It is shown that liquid evaporation rate and the change of a droplet dimension can also be described by characteristic curves.     

Triindolylmethane-based high triplet energy glass-forming electroactive molecular materials

A series of new triindolylmethane-based compounds including those containing reactive functional groups were synthesized by the tandem addition–elimination–(Michael) addition reaction from 1H-indole and 1H-indole-3-carbaldehyde. The thermal, optical, photophysical and photoelectrical properties of the synthesized compounds were studied. The synthesized compounds exhibit moderate thermal stability with 5% weight loss temperatures ranging from 245 to 310 °C and form glasses with glass transition temperatures in the range of 98–123 °C. The ionization potentials of the synthesized compounds measured by the electron photoemission in air technique range from 5.67 to 5.80 eV. The solutions of the synthesized compounds show relatively high triplet energies in the range from 2.97 to 2.99 eV.     

Charge-transporting 3,4-ethylenedioxythiophene-based hydrazone monomers and oligomers

3,4-Ethylenedioxythiophene-based hydrazones, containing reactive functional groups were synthesized and their optical, thermal, photophysical and electrochemical properties were studied. The monomers were subjected to cationic polymerization using boron trifluoride etherate as an initiator. The ionization potentials of the films of the hydrazones, measured by the electron photoemission technique, range from 5.53 to 5.62 eV. Room temperature time-of-flight hole mobilities in the solid solutions of 3,4-ethylenedioxythiophene hydrazone monomers in bisphenol-Z polycarbonate exceed 10^?5 cm² V^?1 s^?1 at high applied electric fields.     

Glass-forming carbazolylidene-containing hydrazones as hole-transporting materials

The synthesis, optical, thermal and photoelectrical properties of carbazole- and phenothiazine-containing hydrazones are reported. The ionization potentials of the films of the hydrazones, measured by the electron photoemission technique, range from 5.20 to 5.60 eV. Room temperature time-of-flight hole mobilities in the solid solutions of carbazole phenothiazine and carbazole carbazole hydrazones in bisphenol-Z polycarbonate exceeded 10^?5 cm²/(V s) at high applied electric fields.     

Glass-forming hole-transporting carbazole-based hydrazone monomers,polymers, and twin compounds

The synthesis, optical, thermal, and photoelectrical properties of new carbazole-based hydrazone monomers, polymers, and twin compounds are reported. All the synthesized materials are capable of glass formation. Their glass transition temperatures range from 27 to 90 °C. The ionization potentials of the films of carbazole-based hydrazones measured by the electron photoemission technique range from 5.18 to 5.48 eV. Hole-drift mobilities in the amorphous films of the synthesized hydrazone monomers measured by the time-of-flight technique at room temperature reach 10^?4 cm²/(V s) at high applied electric fields.     

Thiophene-based hydrazones as hole-transporting materials

The synthesis, optical, thermal and photoelectrical properties of thiophene-based hydrazones are reported. The HOMO levels in a solid state of thiophene-based hydrazones measured by the electron photoemission technique are ?5.25 eV and ?5.28 eV. Hole-drift mobilities of the solid solutions in bisphenol-Z polycarbonate (PC-Z) of the synthesized hydrazones were studied by the time-of-flight technique. Room temperature hole mobilities in the solid solution of thiophene-2-carbaldehyde N,N-diphenylhydrazone in PC-Z exceeded 10^?5 cm²/(V s) at high electric fields.     

Methods for adaptive combination of classifiers with application to recognition of handwritten characters

This paper discusses two techniques for improving the recognition accuracy for online handwritten character recognition: committee classification and adaptation to the user. Combining classifiers is a common method for improving recognition performance. Improvements are possible because the member classifiers may make different errors. Much variation exists in handwritten characters, and adaptation is one feasible way of dealing with such variation. Even though adaptation is usually performed for single classifiers, it is also possible to use adaptive committees. Some novel adaptive committee structures, namely, the dynamically expanding context (DEC), modified current best learning (MCBL), and class-confidence critic combination (CCCC), are presented and evaluated. They are shown to be able to improve on their member classifiers, with CCCC offering the best performance. Also, the effect of having either more or less diverse sets of member classifiers is considered.Received: 17 September 2002, Accepted: 22 October 2002, Published online: 4 July 2003     

Hydrazones containing electron-accepting and electron-donating moieties

Hydrazones containing electron-accepting 1,8-naphthalimide species and electron-donating triphenylamino moieties were synthesized and characterized by nuclear magnetic resonance, infrared spectroscopy, and mass spectrometry. Thermal, optical, electrochemical and photophysical properties of the synthesized derivatives were investigated, their, optical and electrochemical band-gap energies and ionization potentials were established. The hydrazones exhibit initial mass loss temperatures in the range of 268-348 °C and can form glasses with glass transition temperatures in the range of 46-142 °C as established by differential scanning calorimetry. Room temperature time-of-flight hole mobilities in the solid solutions of the derivatives in the polymeric host bisphenol-Z polycarbonate (50%) exceeded 10⁻⁵ cm²/V s at high applied electric fields.     

Conjugation‐Induced Thermally Activated Delayed Fluorescence (TADF): From Conventional Non‐TADF Units to TADF‐Active Polymers

Thermally activated delayed fluorescence (TADF)‐type compounds have great potential as emitter molecules in organic light‐emitting diodes, allowing for electrofluorescence with 100% internal quantum efficiency. In small molecules, TADF is achieved through the formation of intramolecular charge‐transfer states. The only design limitation is the requirement that donor and acceptor entities spatially decouple the highest occupied and lowest unoccupied molecular orbitals, respectively, to minimize exchange splitting. The development of polymeric TADF emitters, on the contrary, has seen comparably small progress and those are typically built up from monomeric units that show promising TADF properties in small molecule studies beforehand. By contrast, herein, a way to achieve TADF properties in cyclic oligomers and polymers composed of non‐TADF building blocks is shown. Due to a strongly decreased energy splitting of the polymer with respect to the individual repeating unit between the lowest singlet and triplet excited state (ΔE_ST) and a sufficiently high radiative decay rate k^S_r, a highly efficient TADF polymer with up to 71% photoluminescence quantum yield is obtained. For the first time, an encouraging method is provided for producing highly efficient TADF oligomers and polymers from solely non‐TADF units via induced conjugation, opening a new design strategy exclusive for polymers.